The ketogenic diet changes the way a person's body gets energy from food. It's usually tried to treat children between
the ages of one and twelve who have seizures that are hard to control.
Some children have fewer seizures on the diet. Some stop having seizures altogether. Some continue to have seizures despite
the diet. In recent years, a few adults have chosen to try the diet, but it is more often prescribed for children.
Normally, our bodies run on energy from glucose, which we get from food. We can't store large amounts of glucose, however.
We only have about a 24-hour supply. When a child has no food for 24 hours, he/she uses up all the stored glucose. With no
more glucose to provide energy, the child's body begins to burn stored fat. The ketogenic diet keeps this process going by
forcing the child's body to burn fat around the clock by keeping calories low and making fat products the primary food that
the child is getting. In fact, the diet gets most (80 percent) of its calories from fat. The rest comes from carbohydrates
and protein. Each meal has about four times as much fat as protein or carbohydrate. The amounts of food and liquid at each
meal have to be carefully worked out and weighed for each person. Doctors don't know precisely why a diet that mimics starvation
by burning fat for energy should prevent seizures, although this is being studied. Nor do they know why the same diet works
for some children and not for others.
When children (or adults) are treated with the ketogenic diet, the dietitian is a very important member of the medical
treatment team. The dietitian works out how much of one type of food or another should be served together to make the diet
work. He/she helps the family plan the child's meals, and works out how many calories the child needs for healthy growth.
Meal plans serve small amounts of fruits or vegetables (carbohydrates) and meat, fish or chicken (protein) with lots and lots
of fat (such as cream, butter, eggs, or mayonnaise), and no sugar.
The following sample meal plans provide a general idea of the kinds of foods that are part of the diet.
Breakfast
- Scrambled eggs with butter
- Diluted cream
- Orange juice
Lunch
- Spaghetti squash with butter and Parmesan cheese
- Lettuce leaf with mayonnaise
- Orange diet soda mixed with whipped cream
Dinner
- Hot dog slices with sugar-free catsup
- Asparagus with butter
- Chopped lettuce with mayonnaise
- Sugar free vanilla cream Popsicle
These examples don't show the exact amounts of each food because those have to be worked out for each child by the dietitian.
Each portion of food must be prepared very carefully by the parents, who often use a gram scale to weigh items exactly.
That's because a tiny mistake in weighing and measuring foods (or if a child finds and eats a few cookie crumbs, or puts anything
containing sugar -- including medicines and toothpaste -- in her mouth), can break the diet's effects -- and cause a seizure.
Often, a period of fine-tuning is needed before it's clear whether or not a child is going to respond to the ketogenic
diet. Doctors often ask parents to try the diet for at least one month, and even as long as two or three, if it's not working
at first. A child on the diet usually continues taking anti-seizure medicine, but may be able to take less of it later on.
If a child does very well, the doctor may slowly taper the medication with the goal of discontinuing it altogether.
About a third of children who try the ketogenic diet become seizure-free, or almost seizure free.
Another third improve but still have some seizures. The rest either do not respond at all or find it too hard to continue
with the diet, either because of side effects or because they can't tolerate the food. A side benefit of the diet is that
many parents say their children are more alert and make more progress when on the diet, even if seizures continue. If the
diet seems to be helping, doctors will usually prescribe it for about two years. Then, they may suggest that parents slowly
begin including regular food in the child's diet to see if the seizures can still be controlled, even with a normal diet.
Sometimes a small amount of seizure medication is started again after the diet is stopped. However, some children may be able
to stay seizure free without any further treatment.
If the seizures return, the doctors may recommend putting the child back on the diet.
Most experts say the diet is worth trying when two or more medications have failed to control seizures, or when medications
cause side effects that are having a harmful effect on a child's life.
It also helps to have a child who is willing to try foods that he might otherwise not be enthusiastic about, and is tolerant
and not fussy about eating. The diet seems to work for more than one kind of seizure, and for children who have a lot of seizures
or few seizures.
But most doctors say it shouldn't be used instead of medications if the drugs are working and the child is not having bad
side effects. Parents generally decide to try the diet because they hope it will give their children a better chance for a
normal life. However, the diet can be a barrier to some normal life experiences for children, especially those that revolve
around food and holidays. And, like other treatments for epilepsy, it also can have side effects that affect some children
more than others can. So, as with any kind of treatment, there's a lot to think about before deciding to try the diet.
It is not a "do it yourself" diet.
Trying to put a child on the diet without medical guidance puts a child at risk of serious consequences. An experienced
treatment team, usually based at a specialized medical center must manage every step of the ketogenic diet process.
The child is placed on a 24-hour fast in a hospital setting and is closely watched to be sure he/she is handling the very
real stress of not getting any food during that time. Once the child begins burning fat for energy instead of glucose (a state
called ketosis), the doctors gradually introduce the foods that are part of the diet in amounts that are right for that child.
When the child goes home, the parents continue to carry out the diet at home, weighing every item and making sure that the
balance between fat and other nutritional elements is maintained. Doctors and dietitians follow children closely to make sure
they're getting enough nutrition and are growing.
Parents of children on the diet use special paper strips to check the ketone level in the child's urine. Ketones are the
chemicals that the body produces when it burns fat. Parents also test urine weekly for blood, which could be an early sign
of kidney stones, a possible side effect of the diet.
Like all the other treatments for epilepsy, the ketogenic diet has some side effects, which may or may not affect
a particular child. Some side effects may go away if caught and managed early on. Knowing what to look for can make a big
difference.
Reported side effects include dehydration, constipation, and, sometimes, complications from kidney stones or gallstones.
The diet lacks several important vitamins, which have to be added through supplements. Sometimes high levels of fat build
up in the blood, especially if a child has an inborn defect in his ability to process fat. This possibility can lead to serious
effects, which is another reason for careful monitoring.